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SubjectRe: [tip:timers/urgent] tick: Fix oneshot broadcast setup really
On Wed, 18 Apr 2012, Suresh Siddha wrote:
> On Wed, 2012-04-18 at 17:31 +0200, Thomas Gleixner wrote:
> From: Suresh Siddha <suresh.b.siddha@intel.com>
> Subject: tick: Fix the spurious broadcast timer ticks
>
> During resume, tick_resume_broadcast() programs the broadcast timer
> in oneshot mode unconditionally. On the platforms where broadcast timer
> is not really required, this will generate spurious broadcast timer ticks
> upon resume. For example, on the always running apic timer platforms with
> HPET, I see spurious hpet tick once every ~5minutes (which is the 32-bit
> hpet counter wraparound time).
>
> Similar to boot time, during resume make the oneshot mode setting of
> the broadcast clock event device conditional on the state of active broadcast
> users.
>
> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>

Sven, Santosh, can you confirm that this works for you on top of the
other two patches?

> ---
> kernel/time/tick-broadcast.c | 3 ++-
> 1 files changed, 2 insertions(+), 1 deletions(-)
>
> diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c
> index bf57abd..766cd82 100644
> --- a/kernel/time/tick-broadcast.c
> +++ b/kernel/time/tick-broadcast.c
> @@ -346,7 +346,8 @@ int tick_resume_broadcast(void)
> tick_get_broadcast_mask());
> break;
> case TICKDEV_MODE_ONESHOT:
> - broadcast = tick_resume_broadcast_oneshot(bc);
> + if (!cpumask_empty(tick_get_broadcast_mask()))
> + broadcast = tick_resume_broadcast_oneshot(bc);
> break;
> }
> }
>
>
>


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